Evolution in Four Dimensions by Eva Jablonka & Marion J. Lamb

Evolution in Four Dimensions by Eva Jablonka & Marion J. Lamb

Author:Eva Jablonka & Marion J. Lamb [Jablonka, Eva & Lamb, Marion J.]
Language: eng
Format: epub, mobi
Published: 2010-12-25T02:03:39.973866+00:00


Whereas the first table focuses on the nature and reproduction of information, the second one summarizes the more Lamarckian aspects of information generation and transmission. It shows whether newly generated variation (1) is blind (“random”) or is targeted to specific activities and functions; (2) passes through developmental filters and is modified before transmission; (3) is constructed by direct planning; (4) can construct a different environmental niche. From the table it is clear that as we move from the realm of genetics to epigenetics and on to behavior and culture, the instructive aspects of variation generation and transmission become more dominant and more diverse. Although with the genetic system there is a small amount of targeting through the various types of interpretive mutations, and there is some filtering through selection among cells during gametogenesis, the role of instructive processes is relatively limited. With epigenetic systems, targeting is much more pronounced. Many epigenetic variations are induced, and the regulatory features of the genetic and cellular networks determine whether and how chromatin marks, self-sustaining loops, and RNA silencing are affected by external signals. Which variants are reproduced in the next generation of cells or organisms depends on the properties of the developmental system and on selection between cellular variants.



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